Pregnancy Body Weight and Neonate Gut Microbiota

Abstract

BackgroundBabies born to overweight/obese (OWOB) moms have elevated obesity risk. A study using culture‐based methods suggested this may be due to neonates' acquisition of obese bacteria from their moms.AimsWe used high‐throughput sequencing to examine if maternal pregravid BMI and pregnancy weight gain are associated with neonate gut microbiota.MethodsWe obtained the 1st (meconium) and 2nd stool from 62 elective C‐section (CS; n=26 OWOB) and 21 vaginally delivered (VD; n=5 OWOB) babies. We consented mothers at a hospital in Porto Alegre, Brazil. Bacterial V4 16S rRNA region was sequenced with the Illumina platform. We performed metagenomic analyses using QIIME and used the linear discriminant analysis (LDA) effect size method, which integrates statistical significance and biologic relevance, to compare microbiota of neonates from moms with pregravid OWOB vs normal BMI, and excess vs normal pregnancy weight gain, by delivery mode.ResultsIn the meconium of CS and VD babies, microbial composition did not vary by pregravid BMI or pregnancy weight gain. The 2nd stool of VD babies from OWOB moms, however, had greater abundance of 11 phylotypes, including the Bacteroides genus, and lower abundance of 23 phylotypes compared to the 2nd stool of VD babies from normal BMI moms. imageIn contrast, only 3 phylotypes differed in the 2nd stool of CS babies from OWOB vs normal BMI moms. Results were similar for pregnancy weight gain and neonate gut microbiota according to delivery mode.ConclusionsPregnancy weight is associated with microbiota from the 2nd (but not 1st) stool of VD (but not CS) neonates, indicating maternal‐offspring transfer of obese bacteria may occur at birth.